The present invention relates to an exchange system on an irremovable machining center, such as a spindle of a processing machine, removable devices such as clamping mandrels, tool holders and similar.
In known systems, the removable device is connected directly to a part of the irremovable machining center, by a coupling means. This removable device may be automatically and rapidly removed from said machining center so as to be replaced for example by another removable device, such as a clamping mandrel, a tool holder, a lathe center holding device and similar having different dimensions, and thus allowing work pieces having different dimensions to be machined, and different tools to be used. Rapid engagement and disengagement means, generally automatic, are further provided between said removable device and said machining center.
A first known embodiment of a connection between the removable device and the machining center consists of a coupling means in the form of ring gears with radial self centering teeth, one ring gear being mounted directly on the removable device and the other directly on the machining center.
This embodiment has numerous drawbacks: it is comparatively expensive; and in particular the precision of the coupling and more particularly the centering of the removable device are insufficient for any precision manufacture and machining, since there is always play between the teeth of the ring gear which may reach several tenths of a millimeter.
In another known embodiment, the connection between the removable device and the machining center consists of a coupling means having a conical projection machined on the machining center which cooperates with the corresponding conical bore machined in a part of the removable device.
This embodiment is also costly. It is unreliable. More particularly it is very difficult, during rapid exchange of a removable device, to obtain correct introduction without shocks of said conical projection into said bore without damaging the parts of the coupling or, at least, rapidly reducing the machining precision.
The aim of the present invention is to overcome these drawbacks.